1. Field of the Invention
The invention relates to signal transmission systems responsive to A.C. signals.
2. Brief Description of the Prior Art
Known in the art are signal transmission systems for transmitting A.C. signals over a signal line in which the signal line is directly connected to the source of the A.C. signals. Such an arrangement suffers from the disadvantage that to avoid the possibility of false interpretation of signals received at the receiving end of the signal line due to spurious signals picked up by the signal line as a result of stray capacitive coupling and the like, either complex signal processing equipment must be used at the receiving end of the signal line, or the signal line must be shielded or made coaxial with its return line. These methods of avoiding misinterpretation of the received signals are expensive and reduce the overall system reliability.
It is an object of the invention to provide an improved signal transmission system. It is a further object of the invention to eliminate the need to shield the signal line or the need to employ complex signal processing equipment for avoiding misinterpretation of received signals due to A.C. pick up in the signal line.